Summary: Coumadin is given to people who have an established thrombus or clot or who at risk to have a clot. An INR and history to include other medicines you take (including Chinese herbs and over-the-counter medicines), other illnesses and diet will determine how much Coumadin you get. Within each of these groups, there are factors that can affect your risk to bleed. In addition, certain genes control how Coumadin is broken down by the body and how Vitamin K is recycled. These two genes can vary from person to person. They can make us differently sensitive to Coumadin, a difference that may explain why some people have bleeding issues with Coumadin within the first month of receiving the drug. Many medicines interact with Coumadin and will alter what dose to start at. Usually, it is common to take 5 mg a day. The commonest response to Coumadin is nothing although there are rare people who will inappropriately have clots. You may feel a painful bruise over your breast or hip. Call your doctor. You need to be very systematically given Coumadin and get frequent blood tests --- an INR --- every other day to increase the safe use of this drug. The INR blood test result early on may reflect a higher risk to bleed a few days later; the INR in the beginning reflects “Coumadin” effects days later more than at the time you had the drug. Coumadin Clinics give you that systematic care with software that searches out the right dose very methodically. Still, it can often take 5 to 7 days to get you to the point where you are adequately anticoagulated.
